1. Field of the Invention
This invention relates to intumescent amine-aldehyde copolymer compositions and more particularly relates to such compositions having improved UV stability.
2. Description of the Prior Art
As taught in U.S. Pat. Nos. 3,912,845 and 3,922,251, valuable intumescent compositions may be obtained by the use of low molecular weight, water-insoluble amine-aldehyde copolymers consisting essentially of repeating units which correspond to the formula: ##STR1## wherein Q is the residue of an alkanal containing 1-5 carbon atoms and R is hydrogen, alkyl, haloalkyl, alkoxy, haloalkoxy, halo, nitro, acetamido, or sulfonamido. These compositions are satisfactory for many applications but have the disadvantage of being susceptible to discoloration by ultra-violet light. Attempts to solve this problem by the incorporation of conventional UV stabilizers have been unsuccessful.